Over the past year, work at the Structural Biology Section involved the use of a system of methods developed in our laboratory (in particular fracture-flip) and their combination with immunogold labeling. To this end we have continued and initiated new collaborative projects in areas of research where the contribution of our expertise and methods can be of immediate interest. Among other areas, current research involves: the immunogold localization of oncogenes and oncogene products (MET, Ski, MUC1); the study of the structure and topochemistry of the membrane skeleton (in activated platelets, as improved by deep-etching, in a hepatoma cell line); cellular and molecular mechanisms of endotoxin shock; nanoanatomy and immunogold labeling of vertebrate nervous tissues and GABA receptor transfected cells; maturation of the mouse mammary tumor virus (MMTV); nanoanatomy and topochemistry of the cell surfaces of protozoan parasites; immunogold fracture-flip cytochemistry of the laminin receptor protein.